Since election day, Rachel Maddow has been beating Sean Hannity in the key demo ratings. Fox News has responded with a juvenile attack on Maddow.

There is something happening in cable news that can no longer be ignored. MSNBC is seriously challenging Fox News. Specifically, Rachel Maddow and Lawrence O’Donnell are regularly beating their Fox News competition in the key 25-54 demo. Last week, Maddow beat Hannity, 378,000 viewers to 352,000 in the demo.

This week Maddow handily defeated Hannity on Monday (394,000-336,000) and Tuesday (388,000-285,000). Even with guest hosts filling in for Maddow on Wednesday and Thursday, Hannity was only able to eek out small wins of 55,000 and 38,000 in the demo. From election day through the end of November, Maddow beat Hannity by 13%.

Hannity’s margin over Maddow in total viewers is inflated by the fact that Fox News is available in more homes than MSNBC. Bill O’Reilly’s show is the only thing keeping Fox News ahead in the primetime demo. If anything ever happens to O’Reilly, Fox News will be in deep trouble.

The biggest sign yet that Fox News knows they have a problem was how they responded to Rachel Maddow being nominated for a Grammy for her spoken word version of Drift.